Free Online Readability Checker
Analyze text readability with Flesch-Kincaid, Gunning Fog, and Coleman-Liau scores
Flesch Reading Ease
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Flesch-Kincaid Grade
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Gunning Fog Index
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Coleman-Liau Index
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About this tool
Check the readability of your text with this free online readability score checker. Paste any text to instantly see scores from four leading readability formulas: Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, and Coleman-Liau Index. Each score is color-coded and labeled with a plain-English reading level. The tool also shows detailed text statistics including word count, sentence count, syllable count, average word length, average sentence length, and the percentage of complex words. When your text scores below a standard readability threshold, you get actionable tips to simplify your writing. Whether you are a writer, student, marketer, or content creator optimizing for clarity, this tool helps you make your text accessible to your target audience. All analysis runs in your browser — no data is sent to any server and no sign-up is required.
Frequently Asked Questions
A readability score estimates how easy or difficult a piece of text is to read. Scores are typically expressed as a US grade level (e.g., Grade 8 means an average 8th grader can understand it) or on a scale like Flesch Reading Ease (0-100, higher is easier).
Flesch Reading Ease rates text on a 0-100 scale. Scores 60-70 are considered standard (understandable by 13-15 year olds). Scores above 80 are easy to read, while scores below 30 are very difficult. It is based on average sentence length and syllables per word.
The Flesch-Kincaid Grade Level converts readability into a US school grade. A score of 8.0 means the text is appropriate for an 8th grader. Most popular writing targets grade 7-8. The formula uses average sentence length and average syllables per word.
The Gunning Fog Index estimates the years of formal education needed to understand text on first reading. It focuses on sentence length and the percentage of complex words (3+ syllables). A score of 12 means the text requires a high school senior's reading level.
The Coleman-Liau Index uses the average number of letters and sentences per 100 words to estimate grade level. Unlike other formulas, it counts characters instead of syllables, making it more reliable for computer analysis since it avoids syllable-counting heuristics.
For general audiences, aim for grade 7-8 (Flesch Reading Ease 60-70). For technical writing, grade 10-12 is acceptable. For web content and marketing, grade 6-8 maximizes engagement. Newspapers typically write at grade 8-10.
Use shorter sentences (under 20 words average). Choose simpler words over complex ones. Use active voice. Break long paragraphs into shorter ones. Avoid jargon unless writing for a specialized audience. Read your text aloud — if you stumble, simplify.
Readability formulas are statistical estimates based on surface features like word and sentence length. They do not measure comprehension, context, or domain knowledge. Use them as guidelines, not absolute measures. Comparing multiple scores gives a more reliable picture than any single formula.
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